U.S. Pat. No. 5,740,900 is related to an apparatus for splitting a product stream. An apparatus for splitting a product stream includes a conveyor belt entering a folder to grip products. The conveying belt comprises first and second product grippers arranged thereon in an endless configuration. The first grippers are selectively rotatable around an axis during movement of the conveying belt to allow for secondary stream of products to be formed. The gripper design used here allows for rotational movement of any other gripper out of the formation of conveyed flat products.
U.S. Pat. No. 4,072,228 discloses an apparatus for evening an imprecated stream of printed products. This configuration comprises a number of revolving entrainment members which are a drag connection with one another. At the region of this conveying active path the entrainment members are guided and at the start of the path driven by a thrust drive and at the end thereof driven by a traction drive. The entrainment members engage the printed products and the thrust and traction drive cause a change in the spacing of the entrainment members and, consequently, in the spacing of the products.
U.S. Pat. No. 4,550,822 shows an apparatus for transporting flat products, especially printed products arriving in an imprecated formation. Printed products arriving in an imprecated product formation are fed to space gripper units of transport device by a belt conveyor. The conveying direction of the belt conveyor forms an acute angle with the transport direction of the transport device. The transporting rate of velocity of the belt conveyor is greater than the transporting rate of velocity of the transport device. Each gripper unit comprises a stationary clamping jaw, a pivotable clamping jaw and a plate-shaped stop. The pivotable clamping jaw is pivoted against the action of a clamping spring by a cam structure or the like. The printed products are first accelerated and than pushed into the open gripper mouth until abutting the stop in order to thereby align the printed products at the region of their leading edges. At the region of their trailing edges, the printed products remain under the conveying action of the belt conveyer and at least until the gripper units are closed.
Existing designs which use springs to provide the gripping force do not allow both, a high gripping force and a large gripper jaw travel due to size and stress constrains on the spring. In addition, current latching gripper designs are prone to turn open and are sensitive to wearing of the latch parts.